The ATmega161 is a low-power CMOS 8-bit microcontroller based on the AVRRISC architecture. By executing powerful instructions in a single clock cycle, the ATmega161 achieves throughputs approaching 1 MIPS per MHz allowing the system designer to optimize power consumption versus processing speed. The AVRcore combines a rich instruction set with 32 general purpose working registers.

All the 32 registers are directly connected to the Arithmetic Logic Unit (ALU), allowing two independent registers to be accessed in one single instruction executed in one clock cycle. The resulting architecture is more code-efficient while achieving throughputs up to ten times faster than
conventional CISC microcontrollers.